Hello, We recently restricted Port 25 inbound access to our mail server from everyone to only giving access to a scope of filtering Frontbridge.com servers configured to relay email for our domain. We are now receiving emails bounces on people trying to send inbound to our users from certain domains. The MX records for our domain list the Frontbridge.com mail relay when using NSLOOKUP but the bounce back messages have the address of our mail server listed as the target?
<firstname.lastname@example.org>: delivery temporarily suspended: connect to
184.108.40.206[220.127.116.11]: Connection timed out
Where 18.104.22.168 is the external address of our email server restricted only to Frontbridge.com.